Population Ecology and Community Ecology

Vocabulary flashcards covering key concepts in population and community ecology.

Population

A group of individuals of the same species in the same area at the same time.

Ecosystem

A biological community of interacting organisms and their physical environment.

Carrying Capacity (K)

The maximum population size of a species that an ecosystem can sustain indefinitely.

Predation

An interaction where one organism (predator) kills and eats another organism (prey).

Mutualism

A symbiotic relationship in which both species benefit.

Commensalism

A relationship between two species in which one benefits and the other is neither helped nor harmed.

Keystone Species

A species that has a disproportionately large effect on its environment relative to its abundance.

Abiotic Factors

Non-living components of an environment, such as sunlight, temperature, and water.

Biotic Factors

Living components of an environment, including plants, animals, and microorganisms.

Survivorship Curves

Graphs that show the likelihood of survival at different ages throughout the life of an organism.

Intrinsic Factors

Biological factors, such as genetics and species adaptations, that affect population size.

Resource Partitioning

The division of resources by species to reduce competition and allow coexistence.

Competitive Exclusion Principle

No two species can occupy the same niche at the same time; one will outcompete the other.

Secondary Succession

The process of ecosystem recovery following a disturbance that leaves the soil intact.

Population Density

The number of individuals per unit area.

Density-Dependent Factor

A factor that affects population growth in a manner directly correlated to the population's size.

Density-Independent Factor

A factor that affects population growth regardless of the population's size.

Exponential Growth

A rapid increase in population size under ideal environmental conditions.

Logistic Growth

Population growth that stabilizes at carrying capacity due to limiting factors.

Community Ecology

The study of interactions among populations in a given area.

What is an ecosystem?

An ecosystem is a community of living organisms interacting with their physical environment, including both biotic and abiotic factors.

What are the two main types of ecosystems?

The two main types of ecosystems are terrestrial ecosystems (land-based) and aquatic ecosystems (water-based), each having distinct characteristics.

Define biodiversity.

Biodiversity refers to the variety of life in a particular habitat or ecosystem, encompassing species diversity, genetic diversity, and ecosystem diversity.

What is a keystone species?

A keystone species is a species that has a disproportionately large effect on its ecosystem relative to its abundance, often maintaining the structure of the ecological community.

Define trophic levels.

Trophic levels refer to the hierarchical levels in an ecosystem based on how organisms obtain energy, typically categorized as producers, primary consumers, secondary consumers, and tertiary consumers.

What is a food chain?

A food chain is a linear representation of how energy and nutrients flow through an ecosystem, illustrating the direct feeding relationships between organisms.

Describe the concept of an ecological niche.

An ecological niche encompasses the role an organism plays in its ecosystem, including its habitat, resource use, and interactions with other species.

What is succession in ecology?

Succession is the process of change in the species structure of an ecological community over time, typically categorized into primary succession and secondary succession.

Define primary succession.

Primary succession occurs in lifeless areas where soil has not yet formed, such as after a volcanic eruption, allowing pioneer species to establish and create soil.

What is the difference between gross primary productivity (GPP) and net primary productivity (NPP)?

GPP is the total amount of energy produced by photosynthesis in an ecosystem, while NPP is the energy available to consumers after the energy used by producers for respiration is subtracted.

Define carrying capacity.

Carrying capacity is the maximum number of individuals of a species that an environment can sustainably support without degrading the ecosystem.

What are biogeochemical cycles?

Biogeochemical cycles are the pathways through which essential elements like carbon, nitrogen, and phosphorus circulate through the ecosystem, involving both biological and geological processes.

What role do decomposers play in an ecosystem?

Decomposers, such as fungi and bacteria, break down dead organic matter, recycling nutrients back into the ecosystem and maintaining soil fertility.

Define ecological resilience.

Ecological resilience is the ability of an ecosystem to absorb disturbances and still retain its basic structure and functionality.

What is a biome?

A biome is a large geographical biotic unit, characterized by its climate, soil, plants, and animals, such as deserts, forests, grasslands, and tundras.

What factors influence climate in an ecosystem?

Climate in an ecosystem is influenced by factors such as latitude, altitude, proximity to water bodies, ocean currents, and prevailing winds.

Describe the significance of the nitrogen cycle.

The nitrogen cycle is crucial for the conversion of nitrogen in the atmosphere into forms usable by living organisms, affecting plant growth and ecosystem productivity.

What is a mutualism interaction?

Mutualism is a type of symbiotic interaction where both species involved benefit, such as bees pollinating flowers while obtaining nectar for food.

What is the role of producers in an ecosystem?

Producers, or autotrophs, are organisms that convert light energy into chemical energy through photosynthesis, forming the base of the food web.

Define a consumer in an ecological context.

Consumers are organisms that obtain energy by consuming other organisms, classified into herbivores, carnivores, omnivores, and detritivores.

What is secondary succession?

Secondary succession occurs in areas where an ecosystem has been disturbed but soil and some organisms still remain, such as after a forest fire.

What is an omnivore?

An omnivore is an organism that eats both plants and animals, playing a versatile role in food webs.

Describe the importance of pollinators in ecosystems.

Pollinators, such as bees and butterflies, facilitate plant reproduction through the transfer of pollen, which is essential for producing seeds and fruits.

What are abiotic factors?

Abiotic factors are the non-living components of an ecosystem, including sunlight, water, temperature, soil, and nutrients.

How do invasive species impact ecosystems?

Invasive species can disrupt local ecosystems by outcompeting native species for resources, altering habitat, and introducing diseases.

What is an energy pyramid?

An energy pyramid is a graphical representation that shows the flow of energy at each trophic level, illustrating that energy decreases as it moves up the levels.

Define ecosystem services.

Ecosystem services are the benefits that humans derive from ecosystems, such as clean water, pollination, carbon storage, and soil fertility.

What is ecological footprint?

An ecological footprint measures the impact of a person or community on the environment, expressed as the amount of land and water area required to sustain their consumption.

What is an interspecific interaction?

Interspecific interactions are relationships between individuals of different species, including competition, predation, parasitism, and mutualism.

Define biotic factors.

Biotic factors are the living components of an ecosystem, including plants, animals, fungi, and microorganisms that interact with one another.

Explain the significance of carrying capacity in population ecology.

Carrying capacity is significant as it helps understand the maximum population size an environment can sustain without experiencing degradation.

What is a food web?

A food web is a complex network of feeding relationships among organisms in an ecosystem, illustrating how energy and nutrients are transferred through multiple pathways.

Define habitat fragmentation.

Habitat fragmentation refers to the process where large, continuous habitats are divided into smaller, isolated patches, often due to human activities like urban development.

What is the role of niche differentiation in ecosystems?

Niche differentiation allows multiple species to coexist by utilizing different resources or habitats, reducing competition and enhancing biodiversity.

Describe the role of mycorrhizae in ecosystems.

Mycorrhizae are symbiotic relationships between fungi and plant roots, improving nutrient absorption and water uptake for plants.

What is the function of decomposers in an ecosystem?

Decomposers break down dead organic matter, recycling nutrients back into the ecosystem and maintaining soil fertility.

Explain the concept of keystone species with an example.

A keystone species is one that has a disproportionately large effect on its ecosystem; for example, sea otters help maintain kelp forest ecosystems by preying on sea urchins.

How does temperature affect enzyme activity in ecosystems?

Enzyme activity generally increases with temperature up to an optimal point, after which it may decrease due to denaturation, influencing metabolic rates in organisms.

What is the role of primary producers in the carbon cycle?

Primary producers, such as plants and phytoplankton, convert atmospheric carbon dioxide into organic molecules through photosynthesis, serving as the base for the food web.

Describe the impact of biomagnification on top predators.

Biomagnification leads to higher concentrations of toxins in top predators, which can result in health issues, reproductive failures, and population declines.

What is the difference between r-selected and K-selected species?

r-selected species produce many offspring with low parental care, favoring rapid population growth, while K-selected species produce fewer offspring with high parental care, optimizing for stable environments.

How can biological diversity affect ecosystem resilience?

Higher biological diversity enhances ecosystem resilience by providing a wider range of responses to environmental changes and disturbances.

Practice AP Question: Discuss the role of succession in the recovery of an ecosystem post-disturbance.

Succession promotes ecosystem recovery by gradually rebuilding species and habitats, first through pioneer species in primary succession or through rapid regrowth in secondary succession.

What is carrying capacity, and how does it influence population dynamics?

Carrying capacity is the maximum number of individuals an environment can sustain; populations fluctuate based on resource availability and environmental conditions.

Explain how soil composition affects plant growth.

Soil composition, including nutrient content, pH, and moisture retention, plays a critical role in determining the types of plants that can thrive in an area.

Practice AP Question: Describe the effect of climate change on species distribution patterns.

Climate change shifts temperature and precipitation patterns, causing species to migrate, adapt, or face increased risk of extinction as habitats change.

What are the impacts of invasive species on native ecosystems?

Invasive species outcompete native species for resources, disrupt food webs, and can lead to a decline or extinction of native populations.

Discuss the carbon cycle's importance in climate regulation.

The carbon cycle regulates climate by controlling atmospheric CO2 levels through processes like photosynthesis, respiration, and decomposition, influencing global temperatures.

Practice AP Question: How do trophic interactions shape community structure?

Trophic interactions define the flow of energy and matter, determining species abundance and diversity within the community, shaping overall ecosystem dynamics.